Most people haven't heard of QNX Software, though they've likely come in contact with it. The real-time operating system is used where software failure can lead to catastrophic consequences, even death - from high-speed trains to air traffic control towers to highway toll systems. It's also used in more than 100 different types of cars on the road.

I think that in situations where there are a small number of elevators this is still true to a certain extent, but more and more, any situation in which there are more than 3 or 4 elevators in the core, is likely to have a traffic control computer coordinating all of the elevators.

After all, how else can they all be on the wrong floor, going in the wrong direction, when you need one?